Biomedical subjects

William E Gooding

Publications and source records attributed to William E Gooding.

36 records · Page 2Linked to original sources

PubMed2004

Quantitative analysis of circulating plasma DNA as a tumor marker in thoracic malignancies.

BACKGROUND: Increased plasma DNA has been found in cancer patients and may have potential as a tumor marker. The objectives of this study were to develop a controlled, quantitative PCR (QPCR) assay to measure plasma DNA and then evaluate plasma DNA concentrations as a tumor marker in patients with thoracic malignancies. METHODS: We developed a QPCR assay for DNA, using the human beta-actin gene. Plasma samples were analyzed from 58 patients with esophageal cancer (EC; 20 banked samples and 38 prospectively collected samples) and 25 patients with lung cancer (LC; all prospectively collected). Control groups consisting of 51 patients with gastroesophageal reflux disease (GERD; 23 banked samples and 28 prospectively collected) and 11 healthy volunteers were also analyzed. RESULTS: The assay had an experimental variability <4%. In our banked samples, the mean concentration of plasma DNA in EC was 819.0 microg/L (range, 46.2-4738.0 microg/L) vs 432.0 microg/L (6.0-2888.0 microg/L) in GERD (P = 0.02). However, the prospectively collected samples had lower DNA concentrations, and there was no difference between cancer patients and controls. The mean DNA concentration was 10.6 microg/L (range, 7.0-14.0 microg/L) in healthy volunteers and 10.5 microg/L (range, 4.0-23.5 microg/L) in GERD controls vs 13.0 microg/L (range, 4.5-46.5 microg/L) in EC and 14.6 microg/L (range, 3.0-30.0 microg/L) in LC. CONCLUSIONS: Our data indicate that plasma DNA concentrations are of limited diagnostic value when samples are prospectively collected and uniformly handled. This is in contrast to previously published results. Qualitative analysis of DNA may be needed if plasma nucleic acids are to be used as a diagnostic tool in cancer screening.

Biomarkers, Tumor↗

PubMed2004

Abrogation of head and neck squamous cell carcinoma growth by epidermal growth factor receptor ligand fused to pseudomonas exotoxin transforming growth factor alpha-PE38.

PURPOSE: This study was undertaken to determine whether low intratumoral doses of the epidermal growth factor receptor ligand-transforming growth factor alpha (TGF-alpha) fused to Pseudomonas exotoxin (TGF-alpha-PE38)-abrogated head and neck squamous cell carcinoma (HNSCC) tumor growth in vitro and in vivo. EXPERIMENTAL DESIGN: In vitro cytotoxicity assays were carried out to determine the sensitivity of HNSCC cells to TGF-alpha-PE38. TGF-alpha-PE38-treated HNSCC cells were examined by immunoblotting for cleaved poly(ADP-ribose) polymerase to evaluate apoptosis. Nude mice bearing established HNSCC xenografts were treated with several doses of TGF-alpha-PE38 to evaluate the antitumor efficacy in vivo. Tumor sections were stained with terminal deoxynucleotidyl transferase-mediated nick end labeling for apoptosis. To determine the effect of oral administration of TGF-alpha-PE38, gavage injections of TGF-alpha-PE38 were administered, and the esophagus and surrounding soft tissue were then stained for apoptotic cells. RESULTS: HNSCC cell lines examined were sensitive to low doses of TGF-alpha-PE38 (EC(50) in the range of 1.6 to 10 ng/mL). HNSCC cells treated with TGF-alpha-PE38 undergo apoptosis. Antitumor effects were observed using 0.1 and 0.03 microg of TGF-alpha-PE38 administered intratumorally. At these doses, the treatment was well tolerated. Tumors treated with the toxin had a higher number of apoptotic cells compared with the control tumors. No apoptotic cells were observed in the pharyngoesophageal tissues of the mice after gavage administration of the toxin suggesting that the toxin could be orally administered without toxicity. CONCLUSIONS: These results indicate that topical or intratumoral administration of low doses of TGF-alpha-PE38 may demonstrate antitumor effects in HNSCC without associated systemic toxicity.

Animals↗

PubMed2004

SRC family kinases mediate epidermal growth factor receptor ligand cleavage, proliferation, and invasion of head and neck cancer cells.

Head and neck squamous cell carcinomas (HNSCCs) are characterized by up-regulation of the epidermal growth factor receptor (EGFR). We previously reported that a gastrin-releasing peptide/gastrin-releasing peptide receptor (GRP/GRPR) autocrine growth pathway is activated early in HNSCC carcinogenesis. GRP can induce rapid phosphorylation of EGFR and p42/44 mitogen-activated protein kinase (MAPK) activation in part via extracellular release of transforming growth factor alpha (TGF-alpha) by matrix metalloproteinases (MMPs). It has been reported that Src family kinases are activated by G-protein-coupled receptors (GPCRs), followed by downstream EGFR and MAPK activation. To further elucidate the mechanism of activation of EGFR by GRP in HNSCC, we investigated the role of Src family kinases. Blockade of Src family kinases using an Src-specific tyrosine kinase inhibitor A-419259 decreased GRP-induced EGFR phosphorylation and MAPK activation. GRP also failed to induce MAPK activation in dominant-negative c-Src-transfected HNSCC cells. Invasion and growth assays showed that c-Src was required for GRP-induced proliferation or invasion of HNSCC cells. In addition to TGF-alpha release, GRP induced amphiregulin, but not EGF, secretion into HNSCC cell culture medium, an effect that was blocked by the MMP inhibitor marimastat. TGF-alpha and amphiregulin secretion by GRP stimulation also was inhibited by blockade of Src family kinases. These results suggest that Src family kinases contribute to GRP-mediated EGFR growth and invasion pathways by facilitating cleavage and release of TGF-alpha and amphiregulin in HNSCC.

Amphiregulin↗

PubMed2004

The gender gap in a surgical subspecialty: analysis of career and lifestyle factors.

BACKGROUND: Although the percentage of women in surgical subspecialties is increasing, little is known about the experiences of these women compared with their male counterparts. OBJECTIVE: To identify career and lifestyle factors that distinguish female otolaryngologists. DESIGN, SETTING, AND PARTICIPANTS: Otolaryngologists were asked to respond to a confidential 119-item questionnaire. The instrument was sent to all 502 female members of the American Academy of Otolaryngology-Head and Neck Surgery who had finished their residency training and were practicing medicine. For response comparison, the survey was mailed to 2 male otolaryngologists who were matched to each female survey recipient for years since completion of training, geographic region, and practice type. RESULTS: Of the 673 respondents (52.6% response rate), women were more likely to be divorced or separated (P =.001) and have fewer children (P <.001). In contrast to men, women reduced their work hours in conjunction with having more children (P <.001). Controlling for professional hours and hours spent in the operating room per week, type of practice, and years since completion of residency, women earned 15% to 20% less per year than men (P <.001). Men relied more on their spouse or partner for household responsibilities and child care (P <.001), and 34.3% of the women (compared with 7.1% of the men) spent 21 to 40 h/wk on household management (P <.001). CONCLUSION: Although male and female otolaryngologists receive equal training opportunities, women earn less money for performing similar jobs and have increased family responsibilities, which may effect their career advancement.

Adult↗

PubMed2004

Mutation of p53 in head and neck squamous cell carcinoma correlates with Bcl-2 expression and increased susceptibility to cisplatin-induced apoptosis.

BACKGROUND: The p53 protein, a well-known tumor suppressor that functions primarily as a transcription factor, initiates cell cycle arrest and apoptosis after genotoxic stress. The antiapoptotic regulator Bcl-2 is a downstream modulator of p53-induced apoptosis. Loss of function of the p53 tumor suppressor through mutation is an important event that contributes to cellular transformation. Mutation of p53 is one of the most common genetic alterations in squamous cell carcinomas of the head and neck (SCCHN). We hypothesized that p53 mutation is associated with Bcl-2 expression and susceptibility to apoptosis in SCCHN. METHODS: Exons 5 to 8 of the p53 gene were sequenced in 22 SCCHN tumor samples and correlated with the Bcl-2 expression and apoptosis rates in these tumors. In addition, a Bcl-2-expressing SCCHN cell line, UMSCC74B, was stably transfected with a temperature-sensitive mutant p53 construct, and Bcl-2 expression levels were examined at the mutant and the wild-type temperatures. RESULTS: Bcl-2 expression was inversely correlated with wild-type p53 status in SCCHN tumors (p = .05). Furthermore, there was a modest increase (1.7-fold) in apoptosis in the wild-type p53 tumors compared with mutant p53 SCCHN. Immunoblotting of UMSCC74B cells stably transfected with the temperature-sensitive mutant p53 construct demonstrated that shifting these cells to the mutant p53 temperature (39.5 degrees C) resulted in decreased expression of Bcl-2 compared with levels in cells grown at the wild-type p53 temperature (32.5 degrees C). Further investigation showed that SCCHN cells expressing predominantly mutant p53 and decreased Bcl-2 were more susceptible to cisplatin-induced apoptosis than vector-transfected controls (p < .0001). CONCLUSIONS: These results suggest that p53 mutation directly modulates Bcl-2 expression and therefore susceptibility to chemotherapy-induced apoptosis in SCCHN cells in vitro.

Antineoplastic Agents↗

PubMed2003

Antitumor effects of epidermal growth factor receptor antisense oligonucleotides in combination with docetaxel in squamous cell carcinoma of the head and neck.

PURPOSE: Antisense approaches targeting the epidermal growth factor receptor (EGFR) have been demonstrated to inhibit the growth of squamous cell carcinoma of the head and neck (SCCHN). Docetaxel is an effective chemotherapeutic agent in the treatment of SCCHN. The present study was undertaken to evaluate the antitumor mechanisms of EGFR antisense (AS) oligonucleotides administered in combination with docetaxel in preclinical models of SCCHN. EXPERIMENTAL DESIGN: SCCHN cells lines and xenografts were treated with an EGFR AS oligonucleotide targeting region 760-779 of EGFR mRNA (GenBank accession XM_004738) alone and in combination with docetaxel. Proliferation in vitro and tumor growth in vivo were examined in addition to determinations of EGFR expression and signaling pathways to evaluate antitumor mechanisms. RESULTS: A combination of docetaxel with EGFR AS resulted in increased cytotoxicity compared with treatment with docetaxel plus EGFR sense oligonucleotides or docetaxel alone after 24 h. Tumor volumes were significantly reduced in the mice treated with a combination of intratumoral EGFR AS and systemic docetaxel compared with mice receiving monotherapy. The combination of docetaxel plus EGFR AS resulted in decreased expression levels of EGFR, phosphotyrosine signal transducers and activators of transcription 3, vascular endothelial growth factor, and pAKT compared with expression levels after either treatment alone. CONCLUSIONS: A combination of EGFR AS and docetaxel may be effective in the treatment of SCCHN with a reduced toxicity profile compared with standard chemotherapy regimens.

Animals↗

PubMed2003

Constitutive activation of Stat5b contributes to carcinogenesis in vivo.

The development of more effective prevention and treatment strategies for solid tumors is limited by an incomplete understanding of the critical growth pathways that are activated in carcinogenesis. Signal transducers and activators of transcription (STAT) proteins have been linked to transformation and tumor progression. Studies to date have not elucidated clear and distinct roles for Stat5genes (Stat5a and Stat5b) in human epithelial cancers. We analyzed the role of Stat5a/b isoforms in squamous cell carcinoma of the head and neck using expression and activation studies in human tissues and in a xenograft model after selective targeting. In a xenograft model, blockade of Stat5b, but not Stat5a, using antisense oligonucleotides resulted in tumor growth inhibition and abrogation of Stat5 target genes in vivo. Blockade of the epidermal growth factor receptor resulted in partial abrogation of Stat5 activation, thus linking epidermal growth factor receptor to Stat5 in vivo. In tissues from 33 individuals with head and neck cancer, Stat5 activation levels were correlated with progression to a malignant phenotype, where increased expression and phosphorylation of Stat5b were detected consistently in tumors compared with their epithelial counterparts. Thus, constitutive activation of Stat5b contributes to squamous cell tumorigenesis and may serve as a therapeutic target.

Animals↗

PubMed2003

Intratumoral delivery of dendritic cells engineered to secrete both interleukin (IL)-12 and IL-18 effectively treats local and distant disease in association with broadly reactive Tc1-type immunity.

Dendritic cells (DCs) were adenovirally engineered to constitutively and durably secrete the potent Th1-biasing cytokines interleukin (IL)-12 (AdIL12DC) and/or IL-18 (AdIL18DC) and evaluated for their ability to promote therapeutic antitumor immunity in murine sarcoma models. Injection of either AdIL12DC or AdIL18DC into day 7 CMS4 or MethA tumors resulted in tumor rejection or slowed tumor growth when compared with control cohorts. Importantly, intratumoral injection with DCs engineered to secrete both IL-12 and IL-18 (AdIL12/IL18DC) resulted in complete and the most acute rejection of any treatment group analyzed. This strategy was also effective in promoting the regression of contralateral, untreated tumors. Both CD4+ and CD8+ T cells were required for tumor rejection. CD8+ splenic T cells from mice treated with AdIL12/IL18DC produced the highest levels of IFN-gamma in response to tumor rechallenge in vitro and displayed the broadest repertoire of Tc1-type reactivity to acid-eluted, tumor-derived peptides among all treatment cohorts. This apparent enhancement in cross-presentation of tumor-associated epitopes in vivo may result from the increased capacity of engineered DCs to kill tumor cells, survive tumor-induced apoptosis, and present immunogenic MHC/tumor peptide complexes to T cells after intratumoral injection. In support of this hypothesis, cytokine gene-engineered DCs expressed higher levels of MHC and costimulatory molecules, as well as Fas ligand and membrane-bound tumor necrosis factor alpha, with the latter markers associated with elevated tumoricidal activity in vitro. Cytokine gene-engineered DCs appeared to have a survival advantage in situ when injected into tumor lesions, to be found in approximation with regions of tumor apoptosis, and to have the capacity to ingest apoptotic tumor bodies. These results support the ability of combined cytokine gene transfer to enhance multiple effector functions mediated by intralesionally injected DCs that may concertedly promote cross-priming and the accelerated immune-mediated rejection of tumors.

Adenoviridae↗

PubMed2003

Epidermal growth factor receptor-stimulated activation of phospholipase Cgamma-1 promotes invasion of head and neck squamous cell carcinoma.

Lymph node metastasis and local invasion of head and neck squamous cell carcinoma (HNSCC) is associated with a poor prognosis. However, little is known about the factors governing tumor cell invasion in HNSCC. Phospholipase Cgamma-1 (PLCgamma-1) contributes to tumor cell invasion in experimental systems when activated by the epidermal growth factor receptor (EGFR). We hypothesized that EGFR overexpression in HNSCC mediates invasion via PLCgamma-1. On EGFR ligand stimulation, phosphorylation of PLCgamma-1 increased in all of the HNSCC cell lines tested (4 of 4). In the presence of EGFR-specific tyrosine kinase inhibitor (PD153035) or an anti-EGFR antibody (C225), PLCgamma-1 activation was abrogated indicating that PLCgamma-1 was downstream of EGFR. Blocking cellular PLC with an inhibitor (U73122) reduced inositol phosphate turnover in all of the HNSCC cell lines examined, and treatment with the PLC inhibitor or antisense oligonucleotides targeting PLCgamma-1 significantly reduced in vitro invasiveness of HNSCC cell lines through Matrigel. To determine the clinical relevance of these findings, we compared levels of PLCgamma-1 in tumor and paired normal tissue from 33 patients with HNSCC. PLCgamma-1 levels were significantly higher (P < 0.0001) in the tumors compared with the normal mucosa of HNSCC patients. Levels of activated PLCgamma-1 were analyzed in 20 patients. Tumors expressed higher levels of phosphorylated PLCgamma-1 compared with normal adjacent mucosa (P = 0.05). Thus, PLCgamma-1 may mediate invasion and metastasis downstream of EGFR in HNSCC.

Aged↗

PubMed2003

Src kinases mediate STAT growth pathways in squamous cell carcinoma of the head and neck.

Signal transducer and activator of transcription (STAT) proteins are constitutively activated in many malignancies, including squamous cell carcinoma of the head and neck (SCCHN). Previously, we reported that phosphorylation of the epidermal growth factor receptor (EGFR) is linked to activation of STATs 3 and 5 in SCCHN cells. The present study was undertaken to determine the role of Src family kinases in STAT activation and SCCHN growth. The Src family kinases c-Src, c-Yes, Fyn, and Lyn were expressed and activated by transforming growth factor-alpha stimulation in all four SCCHN cell lines examined but not in corresponding normal epithelial cells. In nine SCCHN cell lines tested, Src phosphotyrosine expression levels were highly correlated with activation levels of STATs 3 and 5. Co-immunoprecipitation analysis demonstrated interaction between c-Src and STATs 3 or 5 and EGFR in SCCHN cells, but no heterodimerization was detected between STAT3 and STAT5. SCCHN cells treated with either of two Src-specific inhibitors or transfected with a dominant-negative c-Src construct demonstrated decreased activation of STATs 3 and 5 and reduced growth rates in vitro. These results demonstrate a role for Src kinases in mediating activation of STATs 3 and 5 in concert with the EGFR in SCCHN cells. Strategies to target Src activation may contribute to the treatment of cancers that demonstrate increased levels of EGFR and STATs, including SCCHN.

Base Sequence↗

PubMed2003

Radiofrequency ablation of pulmonary malignant tumors in nonsurgical candidates.

OBJECTIVE: Radiofrequency ablation applies thermal energy with a catheter delivery system, resulting in coagulation necrosis. Radiofrequency ablation is frequently used for hepatic malignant tumors, but few reports exist regarding its use for lung tumors. We report our experience with radiofrequency ablation for the treatment of pulmonary malignant tumors. METHODS: We evaluated the results of lung radiofrequency ablation for patients not considered surgical candidates. Indications for radiofrequency ablation were pulmonary malignant tumors in patients with medical comorbidities, pulmonary compromise, or refusal of surgery. RESULTS: Thirty-three lung tumors in 18 patients (12 male, 6 female) were treated with radiofrequency ablation. Tumors included metastatic carcinoma (n = 8), sarcoma (n = 5), and lung cancer (n = 5). Mean age was 60 years (range 27-95 years). Thoracic surgeons performed radiofrequency ablation by minithoracotomy (n = 5) or computed tomography-guided percutaneous methods (n = 13) with patients under general anesthesia in the operating room. Mean length of stay was 3 days (range 1-7 days). Complications included procedure-related pneumothorax in 7 of 13 percutaneous procedures (53.8%), delayed pneumothorax (1/18), pneumonitis/pneumonia (4/18), small pleural effusion (9/18) and transient renal failure (1/18). One death occurred as a result of hemoptysis 19 days after radiofrequency ablation of a central nodule. This patient had also received recent brachytherapy. After a mean follow-up of 6 months (range 1-14 months), radiofrequency ablation had achieved a radiographically determined response in 8 of 12 patients with treated tumors smaller than 5 cm (66.6%). Death with progressive metastatic disease occurred in 7 of 18 patients (38%) during follow-up. CONCLUSION: This pilot study demonstrates the feasibility of radiofrequency ablation for small peripheral lung tumors. Larger tumors responded poorly. Additional trials are needed to determine safety and efficacy.

Adult↗

PubMed2003

Quality of life, functional outcome, and costs of early glottic cancer.

OBJECTIVE: To analyze quality of life, functional outcome, and hidden costs by primary treatment with surgery or radiation therapy in patients with early glottic cancer. STUDY DESIGN: Retrospective study in a tertiary care facility. METHODS: A group of 101 patients with carcinoma in situ and T1 invasive squamous cell carcinoma treated primarily with either surgery or radiation, between January 1990 and December 2000, were identified from searching our tumor registry. Patients completed two previously validated questionnaires and one local questionnaire. Statistical significance was assessed with the rank sum test, chi2 test, or Fisher's Exact test. RESULTS: Questionnaires were completed in 59% (44 of 74) of the surgical cohort and 41% (11 of 27) of the radiation therapy cohort. The primary surgical treatments were endoscopic excision (86%), hemilaryngectomy (12%), and total laryngectomy (1%). Patient-reported problems with swallowing, chewing, speech, taste, saliva, pain, activity, recreation, and appearance showed no difference between the endoscopic excision or radiation therapy cohorts. Comparing endoscopic excision versus radiation therapy, respectively, median number of treatments (2 vs. 35), total median travel distance (150 vs. 660 miles), total median travel time (180 vs. 1440 min), and total median number of hours of work missed (76 vs. 24) all differed significantly (P <.01). CONCLUSIONS: Almost all patients with early glottic cancer, whether treated with surgery or radiation therapy, reported excellent quality of life outcomes and functional results. In addition to actual costs, the hidden costs for radiation therapy versus endoscopic excision were all greater in terms of total number of hours of work missed, total travel time, and total travel distance.

Adaptation, Psychological↗

PubMed2002

Decreased tumor blood flow as measured by positron emission tomography in cancer patients treated with interleukin-1 and carboplatin on a phase I trial.

BACKGROUND: Positron emission tomography (PET) scanning can be used to measure blood flow. When interleukin-1alpha (IL-1) is given in a murine model, it induces acute hemorrhagic necrosis, tumor vascular injury and decreased tumor blood flow, and when given prior to carboplatin, there is enhanced antitumor activity compared to either agent alone. METHODS: In a phase I trial of IL-1 and carboplatin, eligible patients with metastatic disease to the lung had PET scanning performed with (15)O water to assess tumor blood flow before and after IL-1 administration. Doses of IL-1 were 0.03, 0.06, 0.10, 0.15, 0.20 and 0.30 micro g/kg given i.v. over 2 h. At 4 h after IL-1 initiation, carboplatin was administered as a 30-min i.v. infusion at a dose of 400 mg/m(2). Treatment was repeated every 28 days. Other measured parameters included granulocyte kinetics, integrin expression on circulating WBC, and carboplatin pharmacokinetics. Of 16 patients, 11 (8 evaluable) underwent PET scanning before and at 2, 4 and 24 h after IL-1 initiation. RESULTS: Mean measured pretreatment tumor blood flow was 1.82 ml/min per g. At 2, 4 and 24 h it was 1.35, 1.67 and 1.62 ml/min per g respectively. Tumor blood flow was significantly decreased ( P<0.008) at 2 h after IL-1 initiation. In four patients, liver blood flow was measured at the same time-points as tumor blood flow. Liver blood flow was discordant with the tumor blood flow measures, showing no statistically significant change. IL-1 also caused a decreased WBC at 2 h after initiation ( n=14, P=0.025). In addition, polymorphonuclear leukocyte (PMN) and monocyte surface expression of CD11b at 2 h was increased when measured by mean fluorescence intensity flow cytometry (PMN P=0.0269, monocytes P=0.0420). No consistent effect of IL-1 on either carboplatin AUC or platelet nadir was demonstrated. CONCLUSIONS: We conclude that IL-1 has measurable effects on tumor blood flow and causes a significant decrease in blood flow as measured by PET scanning with (15)O water at 2 h after initiation. This decrease is temporally associated with a significant leukopenia and an increased expression of the adhesion integrin CD11b on the circulating cell surface (PMN and monocytes). These results suggest that IL-1 causes decreased tumor blood flow in vivo in human cancer patients, an effect that was temporally related to cytokine-induced peripheral blood cellular changes. Furthermore, our findings suggest that PET scanning may be useful to assess the effect of a systemic antineoplastic agent on tumor blood flow in cancer patients.

Adult↗

PubMed2002

Gastrin-releasing peptide receptor-mediated autocrine growth in squamous cell carcinoma of the head and neck.

BACKGROUND: Gastrin-releasing peptide receptor (GRPR)-mediated autocrine growth appears to be an early marker of susceptibility to tobacco-related lung cancers. Because expression of GRPR, however, has not been reported in squamous cell carcinoma of the head and neck (SCCHN), we investigated its expression and that of its ligand GRP in normal mucosa and SCCHN tissues and the involvement of these proteins in the proliferation of SCCHN cells. METHODS: We assessed GRPR messenger RNA (mRNA) expression in specimens from 25 patients with SCCHN, six control noncancer patients, and 14 SCCHN cell lines by use of quantitative reverse transcriptase-polymerase chain reaction. We used neutralizing GRP monoclonal antibody 2A11 to block the GRP-GRPR interaction in SCCHN cell lines and xenografts and assessed the antibody's effect on proliferation by counting cultured cells or measuring xenograft tumor volume in vivo. All statistical tests were two-sided. RESULTS: Tumor and mucosa tissues, respectively, from SCCHN patients expressed sixfold and fourfold higher levels of GRPR mRNA than normal mucosa tissue from noncancer patients (P<.001). The levels of GRPR expression in the tumor and adjacent normal epithelium of individual patients with SCCHN were correlated (r =.652; P =.001), suggesting that increased GRPR expression is an early event in SCCHN formation. SCCHN cells expressed fivefold higher levels of GRPR mRNA than did cultured normal mucosal epithelial cells (P =.005). GRP stimulated proliferation of SCCHN cells in a dose-dependent fashion (P =.006). Neutralizing GRP monoclonal antibody 2A11 inhibited SCCHN cell proliferation in vitro and in vivo. Median survival was 54 months in patients with higher levels of GRPR mRNA and was not reached in those with lower levels. CONCLUSIONS: GRP and GRPR appear to participate in an autocrine regulatory pathway in SCCHN. Thus, strategies that specifically target GRP and/or GRPR may be effective therapeutic approaches for this disease.

Adult↗

PubMed2002

Rapid, quantitative reverse transcriptase-polymerase chain reaction: application to intraoperative molecular detection of occult metastases in esophageal cancer.

OBJECTIVE: Our earlier data showed that quantitative reverse transcriptase-polymerase chain reaction can discriminate patients with node-negative cancer who are at high risk for recurrence. The objective of this study was to determine whether a new, more rapid quantitative reverse transcriptase-polymerase chain reaction assay could provide this information in a time frame suitable for intraoperative decision making. METHODS: We studied formalin-fixed, archived lymph nodes from 30 patients with histologically determined node-negative esophageal cancer with rapid quantitative reverse transcriptase-polymerase chain reaction to measure expression of carcinoembryonic antigen messenger RNA. We also performed rapid quantitative reverse transcriptase-polymerase chain reaction on 37 snap-frozen lymph nodes from 23 patients. Eleven of the 23 patients had benign esophageal disorders (negative control group). The other 12 had esophageal cancer, 6 with histologically determined positive lymph nodes and 6 with histologically determined negative lymph nodes. RESULTS: In the retrospective analysis of archival tissue from 30 patients with esophageal cancer with histologically determined negative lymph nodes, rapid quantitative reverse transcriptase-polymerase chain reaction predicted disease recurrence with a sensitivity and a specificity of 90% and 80%, respectively, and was comparable to conventional quantitative reverse transcriptase-polymerase chain reaction. In the frozen-tissue analysis rapid quantitative reverse transcriptase-polymerase chain reaction detected significantly higher levels of carcinoembryonic antigen expression in all 12 of the histologically determined positive lymph nodes than in the benign nodes. For 2 of these 12 nodes the intraoperative frozen-section analysis had negative histologic results, and N1 status was determined only on final pathologic examination. Rapid (intraoperative) quantitative reverse transcriptase-polymerase chain reaction discriminated both nodes as positive. Among the 14 histologically determined negative nodes, 1 of 3 nodes from 1 patient showed increased carcinoembryonic antigen according to rapid quantitative reverse transcriptase-polymerase chain reaction, and this patient had a clinical recurrence. CONCLUSIONS: In our study we were able to rapidly discriminate patients with node negative-esophageal cancer who had a high risk of recurrence. In frozen tissues rapid quantitative reverse transcriptase-polymerase chain reaction correlated with final pathologic report for 11 of 12 patients. In the 1 discordant case, the quantitative reverse transcriptase-polymerase chain reaction result was positive and may have detected microscopically occult metastasis, because this patient did have disease recurrence. Rapid quantitative reverse transcriptase-polymerase chain reaction was more sensitive than intraoperative frozen sections for detecting metastatic disease. These data suggest that rapid quantitative reverse transcriptase-polymerase chain reaction may have a prognostic role and could guide intraoperative decisions.

Aged↗

PubMed2002

Glimepiride improves both first and second phases of insulin secretion in type 2 diabetes.

OBJECTIVE: The purpose of this study was to assess the effect of glimepiride on insulin sensitivity and secretion in subjects with type 2 diabetes. RESEARCH DESIGN AND METHODS: After a 2-week washout from prior sulfonylurea therapy, 11 obese subjects with type 2 diabetes underwent euglycemic and hyperglycemic clamp studies before and during glimepiride therapy. RESULTS: Glimepiride resulted in a 2.4-mmol/l decrease in fasting plasma glucose (P = 0.04) that was correlated with reductions in postabsorptive endogenous glucose production (EGP) (16.4 +/- 0.6 vs. 13.5 +/- 0.5 micro mol. kg(-1). min(-1), P = 0.01) (r = 0.21, P = 0.01). Postabsorptive EGP on glimepiride was similar to that of control subjects (12.8 +/- 0.9 micro mol. kg(-1). min(-1), NS). Fasting plasma insulin (66 +/- 18 vs. 84 +/- 48 pmol/l, P = 0.05), and first-phase (19 +/- 8 vs. 32 +/- 11 pmol/l, P = 0.04) and second-phase incremental insulin responses to glucose (48 +/- 23 vs. 72 +/- 32 pmol/l, P = 0.02) improved with glimepiride therapy. Insulin sensitivity did not change with treatment (4.6 +/- 0.7 vs. 4.3 +/- 0.7 micro mol. kg(-1). min(-1). pmol(-1)) and remained below that of control subjects (8.1 +/- 1.8 micro mol. kg(-1). min(-1). pmol(-1), P = 0.04). CONCLUSIONS: The current study demonstrates that glimepiride improves both first and second phases of insulin secretion, but not insulin sensitivity, in individuals with type 2 diabetes.

Aged↗

PubMed2002

STAT3 activation abrogates growth factor dependence and contributes to head and neck squamous cell carcinoma tumor growth in vivo.

Epidermal growth factor receptor (EGFR) is up-regulated and contributes to the loss of growth control in squamous cell carcinoma of the head and neck (SCCHN). Previously, we reported an association between autocrine stimulation of EGFR and constitutive signal transducers and activators of transcription (STAT) 3 activation in SCCHN cells in vitro and in vivo. Here, we evaluated the role of activated STAT3 in tumor progression and EGFR-independent mitogenic signaling. We found that SCCHN cells stably transfected with a dominant active STAT3 construct expressed elevated levels of STAT3 target genes, including Bcl-X(L) and cyclin D1, and demonstrated increased proliferation in vitro and more rapid tumor growth rates in vivo. Cell cycle analysis demonstrated an increased proportion of STAT3 construct transfectants in G(2)-M. These findings provide evidence that constitutive STAT3 activation contributes to tumor growth in SCCHN, independent of the EGFR autocrine axis.

Autocrine Communication↗

PubMedDate not supplied

Lack of toxicity of EGFR antisense gene therapy.

PURPOSE: EGFR is overexpressed in many human cancer cells, including head and neck squamous cell carcinoma (HNSCC). We have previously shown that elevated EGFR levels in the primary HNSCC tumor are associated with decreased survival. Reduction of EGFR tumor expression levels using an antisense EGFR sequence under the control of the U6 small nuclear RNA promoter abrogates tumor growth in a head and neck xenograft model. In support of a phase I clinical trial of an EGFR antisense gene-liposome complex administered to HNSCC patients, we conducted a series of studies to evaluate the safety of intralesional injections of EGFR liposomal antisense gene therapy in normal mice. METHODS: Three dose tiers were examined including the starting DNA-lipid dose for the clinical trial. RESULTS: Tissues and blood were harvested from mice treated with the liposome-mediated gene therapy and control mice at several time points for analysis. In this dosing range, administration of the antisense EGFR DNA-liposome complex had no apparent adverse effect on renal, hepatic and hematologic parameters studied. No major organ pathologic changes were observed. CONCLUSIONS: These results suggest that the toxicity of intralesional EGFR antisense DNA plus liposomes is restricted to a self-limited inflammation at the injection site, and may be well-tolerated in the clinical setting. EGFR antisense gene therapy was reviewed by the Recombinant DNA Advisory Committee and the Food and Drug Administration, and a phase I clinical trial is currently underway in patients with advanced HNSCC.

Animals↗